The disclosure relates to a pendulum-based laser leveling device with calibration guard function, which is able to warn the user when the device requires attention after certain event has happened.
Pendulum-based laser leveling devices are generally used in construction and other fields. Such a laser leveling device may comprise one or more laser diodes carried by a pendulum for generating laser lines. Laser leveling devices are precise and sensitive. The device may not be accurate when it experiences impact forces. However, a laser leveling device is always handled roughly in construction sites and is shared with different users. When the device has subjected to a strong shock, it may need to be checked or calibrated. However, it is not able to tell if the device has been handled properly when a user start the job with the device, so the user may use the device to work at a low precision. Further, a laser leveling device does not work properly under extreme working conditions, like extreme temperatures. For example, the laser diodes each have a permitted operation temperature range. Operation performance and lifetime will be affected if the device works at a temperature beyond the permitted operation temperature range. Thus, it is desired that the user can be warned before usage if some undesirable events had happened to the device or the working temperature is not proper.
Some existing laser leveling devices warn the user through icons on a device LED panel about an abnormal state. However, icons on an LED panel can provide only very limited information, and cannot provide enough information to warn the user that the device may not be in proper condition.